feat(kernel): wave 2 guest OS surface and operator parity

- Extend capability model (featureBits2) and align ADR, protocol, /proc, verify scripts
- Add seed RPC + /proc mirrors for replication queue, MBR failover hints, optional attestation
- Pear bridge: IPC request/response, mirror-drive / HDMS pairing hints, dev diagnostics
- Initd: IdleSec for socket units, units.d drop-ins, richer readiness (e.g. exec:)
- Cron: @reboot and JitterSec-style scheduling
- VFS: Linux-shaped /proc stubs (cgroups, tcp), bounded vfs.watch on safe pseudo paths
- Shell: gated parameter expansion v2; /bin/env -S and --env-file (staged script without ESM export)
- Schemas under docs/schemas; expand contract tests; kernel.ext.d → /proc extensions registry
- Refresh handbook, developer-guide, reference index, package READMEs; keep seeder kernel tree in sync

scripts/README.md

@@ -23,7 +23,7 @@ Exits **0** only when **`kernel/`** and **`packages/bare-os-seeder/kernel/`** co
 
 **Usage:** `node scripts/verify-ctx-api-feature-bits.mjs`
 
-Checks that **`packages/bare-os-booter/lib/bare-os-ctx-api.js`** documents a **`BARE_OS_CTX_API_VERSION`** that matches the contract surface (semver discipline) and that stock kernel feature bits in **`bare-os-protocol`** stay consistent with booter advertisement helpers. Invoked from the root **`pretest`** hook.
+Checks that **`packages/bare-os-booter/lib/bare-os-ctx-api.js`** documents a **`BARE_OS_CTX_API_VERSION`** that matches the contract surface (semver discipline) and that stock kernel feature words (**`STOCK_V1`**, **`STOCK_V2`**) in **`bare-os-protocol`** stay referenced from the booter. Invoked from the root **`pretest`** hook.
 
 ## `stage-release.sh`